I have readseveral forum-posts on this subject.

I have a Volvo 240 GL 1984 sedan, right hand drive.

Recently when beginning to drive along theroad in 4th gear the overdrive suddenly started engaging and disengaging itself several times.

After parking the car for several hours I recommenced travelling and now the overdrive could no longer be engaged and remained dead since.

I looked for the white relay box but cannot find one. Fuse 11 was removed (obviousely bypassed).Some cables from the overdrive switch disappear behind the seatbelt warning light. I cannot find a relay box behind the centre vents or behind and above the fuse column. There is a brownish relay box hanging behind the glove box, but thatmay belong to something else.

Is it possible the original overdrive wiring was somehow modified?

I had the car for 8 years and drove 65 000 km and had never problems with the overdrive.

I would be thankful for any hints or ideas.

 

Is this a manual or Auto? You can usually hear the relay "click" behind the dash when you push the button.

 

Hello bubba 240.

Thanks for your reply.

It is a manual.
The solenoid of this overdrive usually only engages after travelling a few km to warm up.

When it engaged one could hear it clearly. At the moment nothing at all happens.

When reading the other posts on the problem it would appear to be the relay box or perhaps the wiring or may be the solenoid.

My problem is: I cannot find the relay box or I cannot recognize it.

Must go under the car to also test the wiring.

 

The overdrive relay should be behind, and just belowthe centre dash air vents.

To help identify it there will be seven wires coming from five terminals:
Terminal 15 - 1 wire blue and 1 wire either blue or green.
Terminal 86 - 1 wire either green or brown.
Terminal 87 - 1 wire white or yellowand 1 wire yellow.
Terminal 85 - 1 wire red.
Terminal 31 - 1 wire black.

To test the solenoidrun leads from the battery to the solenoid terminals and you will hear if it is working.

 

Hello billofdurham.

Thanks for the useful information.

I will test the solenoid this way and will have another try to locate the overdrive relay.

 

Hello again billofdurham.

I'm just reporting on my actions.

Have tested the overdrive solenoid as instructed: the solenoid works.

Have tested the overdrive **** and found that the copper-plate which connects the two copper prongs in the ON-position was not pressed down hard enough and no power passed through the system in the ON-position when testing the switch-assembly with the light globe system. The barbs on the overdrive **** had lost their elasticity and couldn't hold the copper-plate properly in the ON-position.

I directly connected the wires from the overdrive **** and went for a test run, hoping the overdrive would engage. Butthe overdriveremained dead.

Then I went to look for the relay. After removing some unnecessary and necessary panels I found it exactly there where according to the drawing it is meant to be. It is blue in color as my car has a manual transmission.
Your instructions were absolutely important as it was exactly how you described it. Many thanks again.

There is still a chance that the wiring is somewhere defect, but I shall find out about that after the new relay is installed. It is very difficult to follow the electric cables.

Now I have to find a supplier of the relay here in Australia, which may not be easy.

 

Likely to be dry joints in the relay. If you can solder, open it up and redo all joints on teh circuit board. Much more likely than contacts. Relay probably available from VOlvo, at a price.

 

[:@]It might not be the wiring .
The solonoid could be on its way out .
I pulled mine off of my740 Wd 40ed it & got it working .
I change /pump my fluid every 6 month or so .Making up for former bad maintenance
The solinoid will react to electicity if its working .DC of course.

 

hey guys does anyone have a picture off the solinoid.....

 

Heres a complete tutorial w/ photos, the wire harness can go bad near the solonoid itself.
http://cleanflametrap.com/odwire/

and ,
http://cleanflametrap.com/pub_autoOD/

 

thank you for the link